SH7750 Series

• SH-4 is a high-performance embedded RISC processor using the superscalar architecture.
  SH-4 expands SuperH architecture that is used as an embedded RISC CPU for a wide range of multimedia equipment.
  SuperH is a RISC CPU that has a 16-bit fixed length instruction set for improved code efficiency and is suitable for embedded equipment.

SH-4 has inherited a 16-bit fixed length instruction. Floating-point instructions and cache operation instructions are added. SH-4 has multiply-and-accumulate instructions.

Superscalar CPU

• SH-4 uses a superscalar architecture. There are two pipelines in the processor, and 2-instruction parallel execution is possible.

Superscalar architecture is the technology that executes two or more instructions in one clock. A SH-4 using this technology can execute a maximum of two instructions in one clock. Execution time is half and performance is twice compared with a single-scalar architecture. Fourier transformation and digital filter processing can be performed at high speeds by executing floating-point operations and load/store of data with parallel executions.Power consumption and electromagnetic noise can be reduced because the superscalar architecture can realize same the performance at a lower frequency than a single-scalar architecture.

High Speed DSP Operation by FPU

• SH-4 has powerful FPU (Floating-Point Unit).
  • In 3D graphics, Vector transformation operation (affine transformation) of 3-dimensional coordinates is performed for viewpoint changes, etc.
  • Generally, a 4×4 matrix operation is required for affine transformation processing.
  • A 4×4 matrix operation can be executed in 4cycle pitch because SH-4 has a FTRV instruction.
  • 16 multiplications and 12 additions are executed in four clock cycles.
  • High-speed operation (1.7GFLOPS/240MHz ) can be realized.
• Continuous data transfer to FPU (32-bit × 16, 2-bank registers) can be realized by using superscalar architecture.
• Multiply-and-accumulate operations such as FIR filter, FFT operation, etc. can be executed at high speeds.
  
  FLOPS:Floating point number Operations Per Second

"Load/Store by FMOV instruction" and "FPU operation by FTRV instruction" for FPU Register File can be executed with parallel executions by using the superscalar architecture. Operation can be continued by switching FPU Register File1 and FPU Register File2 when data transfer between one of two Register File and data cache is being performed.

[Description] Above figure shows an example of a matrix operation. First, load data to be operated in the register (FPU Register File), then issue matrix operation instruction FTRV. The following register is the same register. DR8,DR10 = FV8 DR12,DR14 = FV12 DR4,DR6 = FV4 The operation result is stored in the data cache after FTRV instruction is executed.

MMU is built-in. Support general purpose OS such as Windows(R) CE, Linux, etc.

• SH-3, SH3-DSP and SH-4 have MMU(Memory Management Unit) built-in. The MMU is hardware for memory management including memory mapping and protection.
• It is possible to handle logical address space which are visible from software such as applications,etc and physical memory space separately by using MMU.
• By restricting memory area which can be accessed from an application, the effect on the system and OS can be minimized if an application runaways.
  
  * MMU: Memory Management Unit
  * Windows is a registered trademark or trademark of Microsoft Corporation in the US and/or other countries.

<Concept of MMU and logic space> MMU divides physical memory into page units and assigns it to virtual address space (mapping). Virtual logical memory space larger than physical memory space can be provided for software by using this function. Security can be enhanced by executing each application and OS at separate virtual address space.

PCI Controller is built-in (SH7751/SH7751R)

• In multimedia equipment and information equipment, a standard bus like PCI bus is used as an interface with a display and a network and for connecting a storage device and a processor.
• It is good way to use PCI bus as an interface with control devices to bring products into market in a short time.
• Connection with the graphics controller, Ethernet controller, DVD and CD-ROM controller can be realized easily by using SH7751/SH7751R(SH-4) that has PCI controller built-in.